ImageGear for C and C++ on Windows v20.0 - Updated
Headerless Digital Camera RAW
User Guide > File Formats and Compressions > File Formats > File Formats Reference > Headerless Digital Camera RAW

Full Name Headerless Digital Camera file
Format ID IG_FORMAT_HLDCRAW = 114
File Extension(s) *.*
Data Type Raster Image
Data Encoding Binary
Color Profile Support No
Multi-Page Support No
Alpha Channel Support No

ImageGear Supported Versions:

Please see the section ImageGear Supported Digital Camera RAW Formats.

ImageGear Supported Features:

ImageGear Read Support:

ImageGear Write Support:

None

ImageGear Filter Control Parameters:

Filter Control Parameter Type Default Value Available Values Description
APPLY_COLORSPACE_CONVERSION AT_BOOL TRUE TRUE, FALSE

If TRUE, ImageGear converts image from camera color space to linear sRGB color space, using white balance settings from the image metadata. This option is enabled only if RECONSTRUCT_COLORS is TRUE. In order to load the image with custom white balance settings, set APPLY_COLORSPACE_CONVERSION to FALSE and use Camera Raw Color space Conversion API functions after image loading.

If custom color reconstruction is not supported for an image (IG_gui_dspl_adjraw_metadata_is_available returns FALSE), an attempt to read it using non-default settings of RECONSTRUCT_COLORS, APPLY_COLORSPACE_CONVERSION or APPLY_TONE_CORRECTION control parameters will result in an ImageGear error.

See Reconstructing Camera Raw Images Using Custom Parameters for details.

APPLY_TONE_CORRECTION AT_BOOL TRUE TRUE, FALSE

If TRUE, ImageGear adjusts image exposure using image's default settings (baseline exposure) and default setting of 5 for Shadows. This option is enabled only if both RECONSTRUCT_COLORS and APPLY_COLORSPACE_CONVERSION are TRUE. In order to load the image with custom exposure/shadows settings, set APPLY_TONE_CORRECTION parameter to FALSE and use Camera Raw Tone Correction API functions after image loading.

If custom color reconstruction is not supported for an image (IG_gui_dspl_adjraw_metadata_is_available returns FALSE), an attempt to read it using non-default settings of RECONSTRUCT_COLORS, APPLY_COLORSPACE_CONVERSION or APPLY_TONE_CORRECTION control parameters will result in an ImageGear error.

See Reconstructing Camera Raw Images Using Custom Parameters for details.

RECONSTRUCT_COLORS AT_BOOL TRUE TRUE, FALSE

If TRUE, ImageGear performs the following operations during image loading:

  • Linearization. Some cameras store images in a non-linear color space, to increase compression efficiency.
  • Calculation of image Black Level, trimming of the black frame, subtraction of black level. Black level, or Thermal Black is the level of signal produced by heating of the camera rather than by light. Many camera sensors measure the black encoding level using fully masked pixels at the edges of the sensor. ImageGear trims these pixels from the image during loading. Intensities of these pixels are averaged to produce the Black Level value. Black Level should be subtracted from image pixels for correct reconstruction of the image.
  • Intensity stretching according to White Level. White level specifies the maximum intensity that can be recorded by camera sensor, or an intensity at which the sensor's output becomes highly nonlinear. Image intensities between the BlackLevel and WhiteLevel range should be stretched to the full contrast range supported by the image bit depth.
  • Demosaicing. Most of digital cameras store pixels in "mosaic" format. At a given pixel location either a Red, Green, Blue, Cyan, or some other color sample value is recorded. Such images are referred to as "Color Filter Array" type. A two-dimensional matrix called "Color Filter Array pattern" describes positions of pixels of particular color in the mosaic image. In order to recreate the full color values in each pixel, it is necessary to interpolate neighboring pixels.
  • Image rotation. Some camera sensors are rotated by 45 degrees. Such images need to be rotated back.

These operations normally don't require user interaction. After applying these operations, all Camera raw images are converted to linear CMYG or RGB color space and promoted to 16 bits per channel.

APPLY_COLORSPACE_CONVERSION and APPLY_TONE_CORRECTION parameters control the rest of color reconstruction operations.

When RECONSTRUCT_COLORS is FALSE, ImageGear does not perform any color reconstruction operations during image loading. 

If custom color reconstruction is not supported for an image (IG_gui_dspl_adjraw_metadata_is_available returns FALSE), an attempt to read it using non-default settings of RECONSTRUCT_COLORS, APPLY_COLORSPACE_CONVERSION or APPLY_TONE_CORRECTION control parameters will result in an ImageGear error.

See Reconstructing Camera Raw Images Using Custom Parameters for details.

Comments:

Headerless Digital Camera file filter provides support for Digital Camera Raw images that only contain pixel data and no header.

Because of absence of a header, such files can't be detected reliably. ImageGear uses low detection priority for these images, and by default, detection of this filter is disabled. Also, since these files do not contain any metadata describing color reconstruction, ImageGear support level for them is limited to "S2" - pixel decoding only.

Please also see the section Working with ImageGear Digital Camera RAW Filter in Using ImageGear chapter.

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